Most of those injured had been on the road when the storm picked up their vehicles and threw them onto their roofs.

A funnel-shaped cloud had been seen approaching the coast from the Atlantic shortly before the damage was reported.

Funnel clouds are rotating areas of cloud which extend downwards from the base of the main thunderstorm cloud. In themselves they are harmless, but if they develop sufficiently and touch the ground, then they can become powerful tornadoes.

Tornados are triggered by the interaction of two contrasting air types, and can occur almost anywhere. They have been seen in every continent except Antarctica.

In the US, where there is a stark contrast between the hot air from the Gulf of Mexico and the cool air from Canada, tornadoes are often extremely destructive and life-threatening.

In Europe, however, the vast majority of tornadoes are pretty feeble and don’t cause any significant damage. Fortunately the destruction caused by this recent storm in Portugal is rare.

A few more thunderstorms are expected to rumble across the Algarve for the remainder of Saturday, before clearing away for Sunday.